1. Field of the Invention
The present invention generally relates to a broadcast receiving device. More specifically, the present invention relates to a broadcast receiving device for receiving television broadcasts.
2. Background Information
Broadcast receiving devices receive television broadcasts and output the television broadcasts to monitors so that the television broadcasts are visible from outside. The number of channels that can be viewed has been increasing with an increase of popularity of digital broadcasts. There are now more programs that include violence, obscenity, and so forth. Therefore, there is a growing need to control the programs that can be viewed by children, so that the children will not be exposed to such programs.
With some conventional television receiver, a user selects in advance a rating level to be subject to viewing control (see Japanese Laid-Open Patent Application 2000-354209, for example). Rating information indicating viewing control conditions is extracted from a television signal. Specifically, the rating information is transmitted with the television signal. Then, a received rating level corresponding to the rating information is identified. If the received rating level is equal to or lower than the selected rating level, then viewing control is executed. In other words, viewing of the television signal is blocked.
Meanwhile, on Mar. 15, 2006, the FCC (Federal Communications Commission) mandated that broadcast receiving devices shall include a function for acquiring an RRT (Rating Region Table) transmitted in a broadcast and updating a viewing control table (hereinafter referred to as a rating table) based on the acquired RRT (see Code of Federal Regulations, Title 47—Telecommunication, Chapter I, §15.120, “Program blocking technology requirements for television receivers”). The rating table is a table that specifies viewing control conditions preset according to positions in a column direction and positions in a row direction.
Also, program viewing control information specifies the viewing control conditions for each program. The program viewing control information is information included in a program information table (event information table; hereafter referred to as “EIT”). The program viewing control information is transmitted as a CAD (Content Advisory Descriptor). The CAD specifies the viewing control conditions as number information indicating a position in a column direction of the rating table and as number information indicating a position in a column direction (see ATSC (Advanced Television Systems Committee) Standard A/65C, for example).
Therefore, the broadcast receiving device can set whether or not the program viewing control specified by the CAD is to be executed by referring to the rating table. However, referring to ATSC Standards A/65C and A/69a, a transmission period of the EIT which includes the CAD is 0.5 second. A transmission period of the RRT is 60 seconds. Thus, the transmission period of the EIT is shorter than the transmission period of the RRT. Therefore, it happens that the CAD indicating the specific location of an updated RRT is received before the updated RRT is received. The user cannot set whether or not to execute the viewing control corresponding to the CAD until the updated RRT is received.
In view of the above, it will be apparent to those skilled in the art from this disclosure that there exists a need for an improved broadcast receiving device. This invention addresses this need in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure.